<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        div{
            width: 500px;
            margin: 50px auto;
        }
        textarea{
            width: 400px;
            height: 300px;
            resize: none;
            outline: none;
        }
        li{
            background-color: #ccc;
            margin: 5px;
            width: 420px;
            padding: 5px 10px;
        }
        a{
            float: right;
        }
    </style>
</head>
<body>
     <textarea name="" id=""></textarea>
     <button>发布</button>
     <ul></ul>
     <script>
     var btn=document.querySelector('button');
     var text=document.querySelector('textarea');
     var ul=document.querySelector('ul');
     btn.onclick=function(){
         if(text.value==''){
             alert('你没有输入内容');
             return false;
         }else{
             var li=document.createElement('li');
             li.innerHTML=text.value+'<a href="javascript:;">删除</a>';
             ul.insertBefore(li,ul.children[0]);
             var as=document.querySelectorAll('a');
             for(var i=0;i<as.length;i++){
                 as[i].onclick=function(){
                     ul.removeChild(this.parentNode);
                 };
             }
         }
     };
     </script>
</body>
</html>